Magnetic Isolation of Cancer-Derived Exosomes Using Fe/Au Magnetic Nanowires

Abstract

Isolating tumor exosomes (TEX) secreted by cancer cells can provide valuable information about the state of a tumor. Here, we present a method to rapidly isolate TEX using magnetic nanowires (MNWs). Specifically, two sets of Fe/Au segmented MNWs were used to isolate TEX released by canine osteosarcoma cell lines (OSCA 8,32,and 40). These MNWs were prepared by electrodeposition showcasing similar length (2.2(1) μm) and diameter (36(3) nm) but different Fe/Au segment thickness: 120(20)/30( 6) nm (sample A) and 28(7)/3(1) nm (sample B).Magnetic measurements indicate that we can effectively tune the magnetic response of the MNWs by changing their segment thickness, obtaining a more anisotropic behavior for sample A. The internalization of these MNWs by OSCA cells as a function of their concentration has been followed by fluorescence microscopy, and a concentration around 25 μg of Fe/Au MNWs per 3 × 10 5 cells has been defined as optimal. Electron microscopy images have revealed that, once internalized, these MNWs end up residing within lysosomes inside the cancer cells, where they tend to be degraded (especially the Fe segments) and fragmented into smaller pieces. Lower degradation for sample B has been observed and related to differences in the synthesis/functionalization process of both samples. We have hypothesized that these fragments of Fe/ Au MNWs are packaged into TEX released to the medium which can then be isolated via a magnetic stand. This has been tested by carrying out TEX isolation experiments on the OSCA cell and comparing the magnetically isolated TEX with those isolated by using conventional methods based on centrifugation. Nanoparticle tracking analysis (NanoSight) has confirmed that the TEX isolated with MNWs have a comparable size distribution and yield to those obtained by using conventional methods, indicating that our magnetic isolation method can consistently provide relatively high TEX yields in a low-cost and fast way.

Beyond the qualitative description of complex magnetic nanoparticle arrays using FORC measurement

“…Advancement of nanotechnology has extensively expedited the emergence of novel magnetic nanostructures, such as magnetic nanowires (MNWs), in various research areas, including medical treatment [1][2][3][4][5], environmental science [6,7], and quantum devices [8][9][10][11][12]. These magnetic nanostructures have opened numerous opportunities for scientists in different disciplines such as nanomedicine, molecular biology [13][14][15][16], applied physics, and nanostructured materials [17][18][19][20][21][22].…”

Projection method as a probe for multiplexing/demultiplexing of magnetically enriched biological tissues

“…The special cylindrical geometry of MNWs gives rise to a well-dened magnetic anisotropy 16 that makes them suitable for many biological applications, such as MRI contrast, magnetic enrichment, and nanowarming. 11,[17][18][19][20][21] An external eld can be remotely used to physically excite MNWs, which makes them suitable for cell tracking, [22][23][24][25] cells manipulation, 26 cell separation, 27,28 drug delivery and drug activation, 29,30 magnetic hyperthermia, 21 and magneto-elastic ferrogels for tissue engineering. 31,32 Furthermore, the MNWs have shown a high internalization by cells in comparison to other magnetic nanoparticles, such as IONs, improving the enrichment and multiplexing yield.…”

A Guideline for Effectively Synthesizing and Characterizing Magnetic Nanoparticles for Advancing Nanobiotechnology: A Review

“…In another example, Sharma et al observed high internalization of the gold-tipped nickel nanowires into osteosarcoma cells showing high cell activities and proliferation even after internalization of the magnetic nanowires [182,183]. In this direction, Nemati et al enriched canine osteosarcoma cells (OSCA 8, 32, and 40) using iron-gold multi-segmented nanowires and they successfully collected the cancer-derived exosomes with a yield competitive to the commercialized methods [4].…”

“…Advancement of nanotechnology has extensively expedited the emergence of novel magnetic nanostructures by reducing the dimensions to 2D nanomaterials, such as thin films and supperlattices, or 1D nanomaterials, such as magnetic nanowires (MNWs), and even 0D, such as spherical magnetic nanoparticles. The excellent quantum efficiency achieved using these nanomaterials has made them useful building blocks for diverse research areas, including medical treatment [1][2][3][4][5], environmental science [6,7], and quantum devices [8][9][10][11]. These magnetic nanostructures have opened numerous opportunities for scientists in different disciplines such as nanomedicine, molecular biology [12][13][14], applied physics, and nanostructured materials [15][16][17][18][19][20].…”